Migraine headaches occur in approximately 12% of the world population. Therefore, in the United States in the year 2013 there were approximately 36 million people who suffer from this affliction. Although medicines have been created that significantly diminish the suffering of migraine patients, these medicines are often contraindicated and have highly undesirable side effects and many patients do not obtain satisfactory relief from the severe headache pain, nausea and other discomforts associated with migraine. Furthermore, migraine headaches are typically treated after they have become painful, i.e., the treatment is often ineffective in preventing the onset of the migraine headache. A non-invasive, non-drug method for the treatment of migraine headaches would be a remarkable boon for those millions of people all over the world who suffer from these painful and often debilitating experiences.
In 1985, A. T. Barker, et al (Lancet, 1985, pp. 1105-1107) described the use of a coil placed over the scalp which produced a high intensity, time varying, magnetic field. This time varying magnetic field induces an electric current in the cortex of the human brain which can in turn produce certain effects on the activity of brain neurons. This type of system has been given the name Transcranial Magnetic Stimulation (TMS). If continuously repetitive magnetic pulses are applied in this manner, it has been given the name rTMS. If a single pulse is applied, it has been given the name sTMS. If a treatment includes many pulses, but the pulses are not continuous, even though there are several pulses, this treatment is still called a treatment with a multiplicity of sTMS pulses.
In an article from Advances in Therapy, May/June 2001 and entitled “Impulse Magnetic-Field Therapy for Migraine and Other Headaches: A Double-Blind, Placebo-Controlled Study,” by R. B. Pelka, et al, there is described a device using an alternating magnetic field source placed on a ribbon around the patient's neck. All devices were no more than 12 inches from the patient's head. The intensity of the 16 Hz magnetic field at the source was 5 microTesla. For all patients, the field at the brain had to be less than 1.0 microTesla. This field was applied for 4 weeks with some benefit being reported in 1 to 3 weeks. The wearing of such a device for weeks is certainly inconvenient as compared to a single magnetic pulse applied for a fraction of a millisecond or at most, a few such pulses. It is also believed that a magnetic field strength of only 1 microTesla would be totally insufficient to erase the aura that precedes many migraine headaches or to be effective to relieve the headache itself.
In the journal Neurology (Apr. 11, 2000, pp. 1529-1531) it has been reported by B. Boroojerdi, et al that rTMS at a rate of one pulse per second can create a reduction of the excitability of the neurons of the human visual cortex. However, that article did not indicate that TMS or rTMS can be used for preventing the occurrence of migraine headaches or diminishing the intensity or duration of a migraine headache.
In U.S. Pat. No. 6,402,678, Robert E. Fischell et al describe means and methods for the treatment of migraine headaches using a portable device that is placed onto the patient's head. This device is used to create a magnetic pulse that acts upon the neurons of the brain and can eliminate both the aura that occurs prior to a migraine headache and a migraine headache after it has started. However, since the entire device is placed onto the patient's head, it is somewhat awkward for the patient's use. Furthermore, since the triggering controls are also located on the head mounted device, their operation is also somewhat difficult.
In U.S. Pat. No. 8,262,556, Robert E. Fischell et al describe a TMS device that has an insertable USB KEY to provide the device the ability to provide a prescribed set of additional pulses with the device having a pulse counter that limits the allowable total number of pulses that can be delivered before an additional prescription USB key is required. This method does not allow for a pre-specified prescription time period for example, a doctor might desire to have the prescription allow a large number of pulses but only for 3, 6 or 12 months before they would like to review the patient's treatment.
While U.S. Pat. No. 8,262,556 discloses the ability of the TMS device to monitor magnetic pulse strength and provide an error message if it is not within a specified range, it does not disclose a wide range of other important error conditions that should be monitored in a patient operated portable TMS device for the treatment of Migraine headaches.
A device called the “Spring TMS” device has been created by a company called eNeura, Inc. and has been used by many patients for the treatment of migraine headaches. Although this device has been very successful for this treatment, it also has several disadvantages. A first disadvantage is that it is quite large and weighs about 4.0 pounds, which makes it somewhat awkward to be carried in a women's shoulder bag or handbag. Still further, it has two movable handles each having two recessed slide operated switches to operate the device and trigger the treatment delivery. The moveable handles complicate the placement of wires that must extend to the slide switches in those two handles for initiating the magnetic pulse. Furthermore, frequent bending of these handles in order to operate the TMS device has the potential to cause wire breakage. Another less than optimum feature of the Spring TMS device is a copper coil having an elliptical shape that is non-optimum for the creation of the desired magnetic pulse from a point of view of its efficiency of converting drive current into magnetic field strength and its weight. The copper coil has a spherical curvature with a radius of 4.5 inches (11.4 cm). The radius of curvature at the top of many human heads appears measure at about 10 cm. Therefore, having a coil to create the magnetic pulse that has a radius of curvature of approximately 10 cm would be much better suited to concentrate the maximum magnetic pulse intensity into the patient's brain. Furthermore, the use of an aluminum coil has the desirable attribute of being lighter in weight as compared to a copper coil that can create the same intensity of magnetic pulse.
Instructions to operate the Spring TMS device are provided by audio cues and further by graphic icons and text messages displayed on an LCD display on the top surface of the device. The language displayed on the LCD is English. For sales in countries other than those countries where English is the native language, the Spring TMS software must be programmed to provide a language other than English. A maximum of three languages is allowed for the Spring TMS device therefore requiring different firmware for languages beyond the first three. Since there are many countries with large populations of patients having migraine headaches such as Japan, China, India, etc., and particularly in countries that do not use the Roman alphabet, it would be more cost effective to not require support for the language of every country where the device will be used for the treatment of migraine headaches.
The Spring TMS device also uses off the shelf resistors to bleed of any residual energy left in the coil following delivery of a magnetic pulse. The construction of these resistors provides a potential point of life limiting failure for the device as the resistance wires that form the resistor are welded into an end cap that with the huge magnetic pulses causing forces on the wires can break over time.
The Spring TMS device has separate power and charge buttons and stays on for around a minute after a pulse is delivered to allow a follow on pulse to be initiated if more than one pulse is being delivered in a session. Use of 2 buttons makes the device more complex and leaving the power on for longer reduces overall battery life.
Spring TMS also uses a single microcontroller that both interfaces with the user controls and display as well as the charge/discharge circuitry. Using a single microcontroller means the control lines are longer and are more susceptible to noise. The new device with two processors allows control lines to be shorter and oriented optimally on each board to achieve less susceptibility to noise.
Spring TMS has a single cylindrical curve on the surface that is applied to the patient's head that does not help in establishing the correct position up or down for the device with respect to the area of the brain to be treated.
In US patent application (Ser. No. 14/275,927) Fischell et al describe the use of encapsulation or potting to reduce the movement of the magnetic coil including its end wires to reduce the noise level during a pulse and improve device reliability. What is not disclosed are designs that improve the device reliability of other components in the TMS device that are also exposed to the forces generated by the large magnetic pulses.
The current SpringTMS device provides no security capability to ensure that only the prescribed patient can use the device. The SIM card is matched to the device but it can still be borrowed by another person and used.
The current SpringTMS device uses a single charging circuit for its two capacitors and uses only two circuit boards with no special orientation. The large magnetic pulses generated by a TMS device will induce significant forces on individual wires and electrical components that can over time and thousands of pulses result in mechanical failures unless novel design techniques are applied to these wires and components.